Pain is common in emergency medicine. The most effective drugs for severe pain are narcotic analgesics. Narcotics must be given intravenously in order to have rapid effect. Narcotics have idiosyncratic effects and their effects vary widely between patients. Therefore, it is difficult to predict what dose is appropriate for a specific patient.
Narcotics are most commonly used to ease pain and are (and most appropriately) titrated to effect. This means that small doses are given frequently until the patient has an adequate response. Since pain relief and most side effects are subjective, this means that doses are continued until the patient stops requesting more and says they have had enough. In practice, this procedure is difficult and time consuming; as a result, most patients do not receive optimal doses, because if the doses are made small enough and the intervals between them long enough to be safe, titration can easily take a half hour. Because of lengthy titration periods, either a nurse or other provider stays at the bedside during the entire period or the titration is slowed (meaning longer without pain relief) or larger doses/shorter time periods are used (which decreases safety). Using morphine as an example, 2 mg (a safe dose) every 3 minutes (just long enough to get from arm to brain) to 20 mg (a reasonable loading dose) takes 30 minutes.
There is also considerable evidence that when medical staff give pain medications only when patients ask, the patients rarely get enough; a condition known as oligo-analgesia. Worse, this often results in intermittent overdosing. Patients commonly alternate between pain and over sedation when these “prn” orders are used.
The solution to this problem is Patient Controlled Analgesia machines, or PCAs. Current PCAs are electro mechanical devices that patients use to inject their own pain medications when they want them. PCAs reduce both oligo-analgesia and sedation, and patients use less narcotics overall and recover faster.
PCAs are the standard of care on post-operative units, but are rarely used in emergency departments or similar areas. This is because PCAs are quite complicated. PCAs must be individually programmed for each patient. Programming must include dose and interval between doses plus a “lock-out” period. For example: the protocol might be “morphine sulphate, 2 mg every 5 minutes but no more than 10 mg per hour or 20 mg every 4 hours”. This is necessary and useful during a prolonged post-operative stay, particularly since patients are loaded with medication in the post anesthesia recovery area prior to moving to the ward. In addition, PCAs require the medication to be used in a specific container; in this case morphine might be available only in a 30 mg pre filled vial specific for the kind of PCA machine used. For obvious reasons, PCAs require redundancy and fail safe mechanisms. As a result, PCA's are expensive, fragile, and time consuming to set up.
What is needed is a PCA that is specific to the needs of the emergency patient. Since emergency patients start with no pain medication, and because they rarely stay for more than a few hours, what is really needed is a device that they can use to titrate their own loading dose. For emergency patients, maintenance doses are not the issue that they are for admitted patients. The device needs to be quick and easy to set up and use so patients do not need to wait in pain for programming to take place.